U.S. patent application number 16/552212 was filed with the patent office on 2021-03-04 for method for measuring combine header center of gravity and mass.
The applicant listed for this patent is CNH Industrial America LLC. Invention is credited to Jethro Martin, Brent Smith.
Application Number | 20210063265 16/552212 |
Document ID | / |
Family ID | 1000004303305 |
Filed Date | 2021-03-04 |
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United States Patent
Application |
20210063265 |
Kind Code |
A1 |
Smith; Brent ; et
al. |
March 4, 2021 |
METHOD FOR MEASURING COMBINE HEADER CENTER OF GRAVITY AND MASS
Abstract
An agricultural combine having a chassis, an intermediate member
connected to the chassis, a first actuator connecting the chassis
to the intermediate member, a first gauge configured to measure a
first force generated by the first actuator, a header movably
connected to the intermediate member, a second actuator connecting
the header to the intermediate member, a second gauge configured to
measure a second force generated by the second actuator, and a
processing unit operatively connected to the first gauge and to the
second gauge and comprising a processor and a memory, the memory
storing computer readable instructions that, when executed by the
processor, are configured to evaluate the first force and the
second force to determine a position of a center of gravity of the
header relative to the chassis. A method for determining the
position of the center of gravity and weight of the header are also
provided.
Inventors: |
Smith; Brent; (Lititz,
PA) ; Martin; Jethro; (Ephrata, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CNH Industrial America LLC |
New Holland |
PA |
US |
|
|
Family ID: |
1000004303305 |
Appl. No.: |
16/552212 |
Filed: |
August 27, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01D 41/127 20130101;
G01G 19/02 20130101; A01D 41/141 20130101; G01M 1/122 20130101;
A01B 63/108 20130101 |
International
Class: |
G01M 1/12 20060101
G01M001/12; G01G 19/02 20060101 G01G019/02; A01D 41/127 20060101
A01D041/127; A01B 63/108 20060101 A01B063/108 |
Claims
1. An agricultural combine comprising: a chassis configured for
movement on a surface; an intermediate member movably connected to
the chassis; a first actuator connecting the chassis to the
intermediate member and configured to move the intermediate member
relative to the chassis; a first gauge configured to measure a
first force generated by the first actuator; a header movably
connected to the intermediate member; a second actuator connecting
the header to the intermediate member and configured to move the
header relative to the intermediate member; a second gauge
configured to measure a second force generated by the second
actuator; and a processing unit operatively connected to the first
gauge and to the second gauge and comprising a processor and a
memory, the memory storing computer readable instructions that,
when executed by the processor, are configured to evaluate the
first force and the second force to determine a position of a
center of gravity of the header relative to the chassis.
2. The agricultural combine of claim 1, wherein the computer
readable instructions, when executed by the processor, are
configured to evaluate the first force and the second force to
determine a mass of the header.
3. The agricultural combine of claim 1, wherein: the first actuator
comprises a first hydraulic cylinder and the first gauge comprises
a first pressure sensor configured to measure a first pressure of a
first volume of liquid in the first hydraulic cylinder; and the
second actuator comprises a second hydraulic cylinder and the
second gauge comprises a second pressure sensor configured to
measure a second pressure of a second volume of liquid in the
second hydraulic cylinder.
4. The agricultural combine of claim 3, wherein the computer
readable instructions, when executed by the processor, are
configured to determine the first force as a function of the first
pressure, and to determine the second force as a function of the
second pressure.
5. The agricultural combine of claim 1, wherein the processor is
configured to determine the position of the center of gravity of
the header relative to the chassis by comparing the first force and
the second force to a plurality of known geometric relationships of
the intermediate member and the header.
6. The agricultural combine of claim 5, wherein: the intermediate
member is connected to the chassis at a first pivot connection; the
first actuator is connected to the intermediate member at a first
actuator connection point; the header is connected to the
intermediate member at a second pivot connection; and the second
actuator is connected to the header at a second actuator connection
point.
7. The agricultural combine of claim 6, wherein the plurality of
known geometric relations comprises: a first distance between the
first pivot connection and the second pivot connection, a second
distance between the first pivot connection and the first actuator
connection point, and a third distance between the second pivot
connection and the second actuator connection point.
8. The agricultural combine of claim 1, wherein the processor is
configured to determine the position of the center of gravity of
the header relative to the chassis by comparing the first force and
the second force to a lookup table comprising a plurality of
predetermined center of gravity positions stored as functions of
respective values of the first force and the second force.
9. The agricultural combine of claim 1, wherein the intermediate
member comprises a feeder housing.
10. A method for determining a center of gravity of a header that
is movably connected to a chassis of the agricultural vehicle by an
intermediate member, the method comprising: measuring a first force
required to hold the intermediate member at a first position
relative to the chassis; measuring a second force required to hold
the header at a second position relative to the intermediate
member; and comparing the first force and the second force to a
plurality of known geometric relationships of the intermediate
member and the header to determine a position of a center of
gravity of the header relative to the chassis.
11. The method of claim 10, further comprising comparing the first
force and the second force to the plurality of known geometric
relationships of the intermediate member and the header to
determine a mass of the header.
12. The method of claim 10, wherein: the first force comprises a
force calculated from a pressure of a first volume of liquid in a
first actuator configured to move the intermediate member relative
to the chassis; and the second force comprises a force calculated
from a pressure of a second volume of liquid in a second actuator
configured to move the header relative to the intermediate
member.
13. The method of claim 10, wherein: the intermediate member is
pivotally connected to the chassis to rotate about a first pivot
connection; the first force is applied to the intermediate member
at a first point; the header is pivotally connected to the
intermediate member to rotate about a second pivot connection; and
the second force is applied to the intermediate member at a second
point.
14. The method of claim 13, wherein the plurality of known
geometric relationships comprises: a first distance between the
first pivot connection and the second pivot connection, a second
distance between the first pivot connection and the first point,
and a third distance between the second pivot connection and the
second point.
15. The method of claim 14, wherein comparing the first force and
the second force to the plurality of known geometric relationships
of the intermediate member and the header to determine the position
of the center of gravity of the header relative to the chassis
comprises actively calculating the position of the center of
gravity based on one or more predetermined equations.
16. The method of claim 14, wherein comparing the first force and
the second force to the plurality of known geometric relationships
of the intermediate member and the header to determine the position
of the center of gravity of the header relative to the chassis
comprises comparing the first force and the second force to a
lookup table comprising a plurality of predetermined center of
gravity positions stored as functions of respective values of the
first force and the second force.
17. The method of claim 10, wherein the agricultural vehicle
comprises a combine, and the intermediate member comprises a feeder
housing.
Description
BACKGROUND OF THE INVENTION
[0001] Agricultural combines typically include a header that is
movably attached to the chassis of the vehicle by a feeder housing.
During operation, the header might be raised or lowered to account
for variations in the ground level, properties of the particular
crop being harvested, and various other operating conditions. The
header can represent a substantial portion of the combine's total
weight. As such, the header is often modeled in the vehicle control
system--such as an automatic header height control system--as a
pendulum suspended at the front of the combine. The automatic
header height control system uses the header model to establish
expected dynamic response properties and an oscillation frequency
of the header to help control the position of the header during
operation.
[0002] In some cases, the dynamic model of the header can remain
essentially fixed, such as when a header is always used in the same
configuration on the same vehicle. However, the header can be
modified for different uses, and different headers (e.g., wider or
narrow headers or headers configured for different crop types) can
often be mounted onto the same vehicle at different times. When
such changes are made, or when a new header is fitted to a combine
vehicle, a process may be used to estimate the header mass. For
example, the header lift actuators may be activated to raise the
header above the ground, and the resulting hydraulic pressure
required to lift the header is measured. This pressure can be
converted into a force measurement, and the force on the actuator
can be converted to a vertical force representing the estimated
weight of the header.
[0003] While helpful, this process is somewhat deficient because
the weight estimate requires one to either know or assume the
position of the center of gravity of the header. For example, a
header that requires a particular force to raise off the ground
could be a relatively light header having a center of gravity
positioned relatively far from the feeder housing, or a relatively
heavy header having a center of gravity positioned relatively close
to the feeder housing.
[0004] The inventors have determined that the state of the art
still requires further advancement, particularly in regard to
providing more accurate measurements of header mass and center of
gravity.
[0005] This description of the background is provided to assist
with an understanding of the following explanations of exemplary
embodiments, and is not an admission that any or all of this
background information is necessarily prior art.
SUMMARY OF THE INVENTION
[0006] In one exemplary aspect, there is provided an agricultural
combine having a chassis configured for movement on a surface, an
intermediate member movably connected to the chassis, and a header
movably connected to the intermediate member. A first actuator
connects the chassis to the intermediate member and is configured
to move the intermediate member relative to the chassis. A first
gauge is configured to measure a first force generated by the first
actuator. A second actuator connects the header to the intermediate
member and is configured to move the header relative to the
intermediate member. A second gauge configured to measure a second
force generated by the second actuator. A processing unit is
operatively connected to the first gauge and to the second gauge
and includes a processor and a memory. The memory stores computer
readable instructions that, when executed by the processor, are
configured to evaluate the first force and the second force to
determine a position of a center of gravity of the header relative
to the chassis.
[0007] In some aspects, the computer readable instructions, when
executed by the processor, are configured to evaluate the first
force and the second force to determine a mass of the header.
[0008] In some aspects, the first actuator comprises a first
hydraulic cylinder and the first gauge comprises a first pressure
sensor configured to measure a first pressure of a first volume of
liquid in the first hydraulic cylinder, and the second actuator
comprises a second hydraulic cylinder and the second gauge
comprises a second pressure sensor configured to measure a second
pressure of a second volume of liquid in the second hydraulic
cylinder. The computer readable instructions, when executed by the
processor, may be configured to determine the first force as a
function of the first pressure, and to determine the second force
as a function of the second pressure.
[0009] In some aspects, the processor is configured to determine
the position of the center of gravity of the header relative to the
chassis by comparing the first force and the second force to a
plurality of known geometric relationships of the intermediate
member and the header. The intermediate member may be connected to
the chassis at a first pivot connection, the first actuator may be
connected to the intermediate member at a first actuator connection
point, the header may be connected to the intermediate member at a
second pivot connection, and the second actuator may be connected
to the header at a second actuator connection point. The known
geometric relations may include: a first distance between the first
pivot connection and the second pivot connection, a second distance
between the first pivot connection and the first actuator
connection point, and a third distance between the second pivot
connection and the second actuator connection point.
[0010] In some aspects, the processor is configured to determine
the position of the center of gravity of the header relative to the
chassis by comparing the first force and the second force to a
lookup table comprising a plurality of predetermined center of
gravity positions stored as functions of respective values of the
first force and the second force.
[0011] In some aspects, the intermediate member comprises a feeder
housing.
[0012] In another exemplary aspect, there is provided a method for
determining a center of gravity of a header that is movably
connected to a chassis of the agricultural vehicle by an
intermediate member. The method includes: measuring a first force
required to hold the intermediate member at a first position
relative to the chassis; measuring a second force required to hold
the header at a second position relative to the intermediate
member; and comparing the first force and the second force to a
plurality of known geometric relationships of the intermediate
member and the header to determine a position of a center of
gravity of the header relative to the chassis.
[0013] In some aspects, the method includes comparing the first
force and the second force to the plurality of known geometric
relationships of the intermediate member and the header to
determine a mass of the header. The first force may be a force
calculated from a pressure of a first volume of liquid in a first
actuator configured to move the intermediate member relative to the
chassis, and the second force may be a force calculated from a
pressure of a second volume of liquid in a second actuator
configured to move the header relative to the intermediate member.
The intermediate member may be pivotally connected to the chassis
to rotate about a first pivot connection, the first force may be
applied to the intermediate member at a first point, the header may
be pivotally connected to the intermediate member to rotate about a
second pivot connection, and the second force may be applied to the
intermediate member at a second point. The known geometric
relationships may include: a first distance between the first pivot
connection and the second pivot connection, a second distance
between the first pivot connection and the first point, and a third
distance between the second pivot connection and the second point.
Comparing the first force and the second force to the plurality of
known geometric relationships of the intermediate member and the
header to determine the position of the center of gravity of the
header relative to the chassis may include actively calculating the
position of the center of gravity based on one or more
predetermined equations. Comparing the first force and the second
force to the plurality of known geometric relationships of the
intermediate member and the header to determine the position of the
center of gravity of the header relative to the chassis comprises
comparing the first force and the second force to a lookup table
comprising a plurality of predetermined center of gravity positions
stored as functions of respective values of the first force and the
second force.
[0014] In some aspects of the method, the agricultural vehicle
comprises a combine, and the intermediate member comprises a feeder
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of inventions will now be described, strictly by
way of example, with reference to the accompanying drawings, in
which:
[0016] FIG. 1 illustrates an example of an agricultural combine
having a header.
[0017] FIG. 2 is a schematic side view of the example of FIG.
1.
[0018] FIG. 3 is a detailed schematic side view of the example of
FIG. 1
[0019] FIG. 4 is a free body diagram illustrating a method for
determining the weight and position of the center of gravity of a
header.
[0020] FIG. 5 schematically illustrates an exemplary control unit
for determining the weight and position of the center of gravity of
a header.
[0021] FIG. 6 is an exemplary process for determining the weight
and position of the center of gravity of a header.
[0022] In the figures, like reference numerals refer to the same or
similar elements.
DETAILED DESCRIPTION OF THE DRAWINGS
[0023] Exemplary embodiments of the present invention provide
methods and apparatus for determining the position of the center of
gravity and/or weight of a header attached to an agricultural
combine or other equipment. It will be appreciated that other
embodiments may be used in other type of machine having a similar
arrangement of parts, upon incorporation of the appropriate
features of the inventions herein.
[0024] FIGS. 1 and 2, illustrate an example of an agricultural
combine 100. The combine 100 has a chassis 102 that is supported
for movement on the ground by wheels 104 or tracks. A header 106 is
attached to the combine 100 and configured to receive crop material
and covey such material to a threshing and separating system 108
located in or on the chassis 102. The threshing and separating
system 108 separates grain from the remaining crop material (also
known as "material other than grain" or "MoG") and a grain elevator
110 conveys the grain to a grain hopper 112. The MoG is discharged
from the back of the combine through one or more openings, which
may include a spreader 114 to better distribute the MoG on the
ground. An unloader 116, such as a movable conduit having an auger
or unloading belt may be provided to remove the grain from the
hopper 112. The header 106 is movably connected to the chassis 102
by an intermediate member, such as a feeder housing 118. The header
106 may comprise any variety of crop processing equipment, such as
crop reels (not shown), cutters, crop dividers 112, augers 120 or
belts to move crop material towards the feeder housing, or the
like. The feeder housing 118 typically includes belt or chain
driven slats or paddles to project the crop materials back to the
chassis 102. In use, the combine 100 is driven in a forward
direction F with the header 106 in proximity to the ground to
process the crop material in front of the combine 100. The
operation and construction of the foregoing components of the
combine 100 are well-known in the art and need not be described in
greater detail herein.
[0025] FIG. 3 shows the connection between the chassis 102 and the
header 106 in more detail. The feeder housing 118 is movably
connected to the chassis 102 at a first movable connection, such as
a first pivot connection 300, and the header 106 is movably
connected to the feeder housing 118 at a second movable connection,
such as a second pivot connection 302. The pivot connections 300,
302 may comprise any suitable arrangement of pivot pin connectors
or the like. Alternatively, one or both movable connections may be
provided to the form of linkage arms or other connectors that allow
pivoting, rotational, parallel traversing, sliding, or other
relative motion between the parts.
[0026] A first actuator 304 is provided to control motion (in this
case, pivoting motion) of the feeder housing 118 relative to the
chassis 102. The first actuator 304 may comprise, for example, a
conventional feeder housing lift cylinder or the like. A second
actuator 306 is provided to control motion (again, pivoting motion)
of the header 106 relative to the feeder housing 118. The second
actuator 306 is provided to tilt the header 106 forwards and
backwards relative to the feeder housing 118, and may be provided
along with the second pivot connection 302 as a faceplate connector
between the header 106 and feeder housing 118. The rotation axes of
the first pivot connection 300 and second pivot connection 302
preferably are parallel.
[0027] Each of the first and second actuators 304, 306 may comprise
any suitable mechanism. In this example, the first actuator 304 and
the second actuator 306 each comprises one or more telescoping
hydraulic piston and cylinder assemblies, which are operatively
connected via hydraulic lines to a source of pressurized hydraulic
fluid and valves appropriate to provide the desired motion control.
It will be appreciated that the term "actuator" is intended to
cover a single mechanism or plural mechanisms operated together to
achieve the desired motion control.
[0028] Each actuator 304, 306 has an associated gauge to determine
the force being generated by the actuator 304, 306. In this case, a
first pressure transducer 308 is provided to measure the pressure
of a first volume of hydraulic fluid in a cylinder of the first
actuator 304, and a second pressure transducer 310 is provided to
measure the pressure of a second volume of hydraulic fluid in a
cylinder of the second actuator 306. The pressure transducers 308,
310 each provide a respective electric signal that is proportional
to the amount of pressure within the respective cylinder. The
electric signals are calibrated to indicate internal pressure
values, and the internal pressure values can be converted to
respective operating forces by multiplying the pressure by the
effective area of the associated piston. The force values can
alternatively be determined based on a calibration between the
output signals and empirically-determined force values, or by other
methods as known in the art.
[0029] The pressure transducers 308, 310 (or other force gauges as
might be used) are operatively connected via wires or wireless
communication to a processing unit 312. The processing unit (an
example of which is described in more detail subsequently herein)
is configured to evaluate the output of the pressure transducers
308, 310 to determine the weight of the header 106, and a position
of the center of gravity of the header 106 relative to the chassis
102.
[0030] One method for determining the weight and position of the
center of gravity is illustrated in FIG. 4, which is a free body
diagram of the header 106, feeder housing 118 and actuator system.
For simplicity, the diagram is illustrated to resolve the forces
and distances into their horizontal and vertical components. The
horizontal axis H and vertical axis V are illustrated in FIG.
3.
[0031] When the feeder housing 118 is raised to hold the header 106
at a stationary position above the ground, the rotation forces
(i.e., moments) about the first pivot connection 300 and second
pivot connection 302 are balanced and equal to zero. A first
actuator force F1 generated by the first actuator 304 acts on the
feeder housing 118 at a location between the first pivot connection
300 and the second pivot connection 302. In practice, the first
actuator 304 generates a vector force oriented along the sliding
axis of the first actuator 304, but the magnitude of this force can
be converted to an equivalent first actuator force F1 located at a
first equivalent distance L1 from the first pivot connection 300
based on the known geometric configuration of the feeder housing
118 and first actuator 304. With the parts in equilibrium, the
moment about the first pivot connection 300 generated by the first
actuator force F1 at the first equivalent distance L1 is equal and
opposite the moment generated by the weight Fg (i.e., mass gravity
force) of the header 106 at the distance Lg of the header's center
of gravity 402 from the first pivot connection 300. Thus, with the
parts in equilibrium the following mathematical relation is
satisfied:
F1*L1=Fg*Lg (Equation 1)
[0032] Similarly, a second actuator force F2 generated by the
second actuator 306 acts between the header 106 and the feeder
housing 118 to hold the header 106 at a fixed position relative to
the feeder housing 118. In practice, the second actuator 306
generates a vector force oriented along the sliding axis of the
second actuator 306, but the magnitude of this force can be
converted into an equivalent second actuator force F2 located at an
equivalent second distance L2 from the second pivot connection 302
based on the known geometric configuration of the header 106 and
the second actuator 306. With the parts in equilibrium, the moment
about the second pivot connection 302 generated by the second
actuator force F2 at the second equivalent distance L2 is equal and
opposite to the weight Fg of the header 106 at a third distance L3
as measured from the second pivot connection to the center of
gravity 402 of the header 106. This third distance L3 is equal to
the distance Lg from the first pivot connection 300 to the header
center of gravity 400, minus the horizontal distance Lf from the
first pivot connection 300 to the second pivot connection 302
(i.e., L3=Lg-Lf). Thus, with the parts in equilibrium the following
mathematical relation is satisfied:
F2*L2=Fg*(Lg-Lf) (Equation 2)
[0033] It will be appreciated from the foregoing that the system
illustrated in FIG. 4 can be defined according to two equations,
and therefore the two equations can be used to solve for up to two
unknown values. In this case, the unknown values are the distance
to the header center of gravity Lg, and the weight Fg of the header
106. The foregoing equations can be solved for both unknowns,
resulting in the following equations:
Fg=(F1*L1-F2*L2)/Lf (Equation 3)
Lg=(F1*L1)/Fg (Equation 4)
[0034] It will be appreciated that some of the variables, such as
the horizontal distance Lf between the first connection 300 and the
second pivot connection 302, can vary depending on the geometric
configuration of the parts. Such variations can be accounted for by
including appropriate correction factors, performing the
measurement at predetermined geometric positions, measuring the
value during each evaluation to determine center of gravity and
mass, and so on.
[0035] It will also be appreciated that the foregoing method
provides only the horizontal position of the header center of
gravity distance Lg. It is expected that this is sufficient for
most or all applications to determine the appropriate dynamic model
and oscillation frequency of the header 106. However, it also may
be possible to evaluate or estimate the vertical position of the
center of gravity by taking additional force measurements with the
parts in different relative orientations. For example, the second
actuator 306 may be operated to move the header 106 to multiple
angular positions relative to the feeder housing 118 to provide an
indication of how far the center of gravity moves in the horizontal
plane as a function of such rotation, which can be used to evaluate
or estimate a vector position in the horizontal and vertical
directions of the center of gravity relative to the second pivot
connection 302.
[0036] The foregoing embodiment provides control of the feeder
housing 118 and header 106 positions by using hydraulic actuators,
and measurement of the cylinder pressures, and thus the forces
exerted by the actuators, using hydraulic pressure transducers.
However, the first and second actuators 304, 306 alternatively may
comprise electric motors or other suitable devices to move the
parts relative to one another, and the pressure sensors 308, 310
may be replaced by other mechanisms to detect force, such as strain
gauges, mechanical scales, and the like. Other alternatives and
variations will be apparent to persons of ordinary skill in the art
in view of the present disclosure.
[0037] FIG. 5 schematically illustrates a processing unit 312
configured to evaluate the position of the center of gravity and
weight of a header 106, but it will be appreciated that both of
these functions are not necessarily required. For example,
embodiments may be configured to calculate only the position of the
header's center of gravity relative to the chassis 102, or only the
weight of the header 106. The processing unit 312 generally
includes any suitable arrangement of processors and logical
circuits, hardware and programming code effective to perform and
present the desired calculations. Here, the exemplary processing
unit 312 comprises a central processing unit (CPU) 500, which is
responsible for performing calculations and logic operations
required to execute one or more computer programs or operations.
The CPU 500 is connected via a data transmission bus 502 to sensors
504 (e.g., pressure transducers 308 and 310), a user interface 506,
and a memory 508. The user interface 506 may comprise any suitable
connection port or the like for programming and customizing the
operation of the processing unit 312. The processing unit 312 also
may have a communication port 510 that is operatively connected
(wired or wirelessly) to other combine control systems such as the
actuators 304, 306 for transmitting control signals to place the
actuators 304, 306 into the desired position or positions for
collecting data from the pressure transducers 308, 310. One or more
analog to digital conversion circuits may be provided to convert
analog data from the sensors 308, 310 to an appropriate digital
signal for processing by the CPU 500, as known in the art.
[0038] The CPU 500, data transmission bus 502 and memory 508 may
comprise any suitable computing device, such as an INTEL ATOM E3826
1.46 GHz Dual Core CPU or the like, being coupled to DDR3L
1066/1333 MHz SO-DIMM Socket SDRAM having a 4 GB memory capacity or
other memory (e.g., compact disk, digital disk, solid state drive,
flash memory, memory card, USB drive, optical disc storage, etc.).
The selection of an appropriate processing system and memory is a
matter of routine practice and need not be discussed in greater
detail herein.
[0039] The memory 508 stores computer readable instructions that
are loaded and executed by the CPU 500 to obtain sensor data from
the sensors 308, 310, and determine the position Lg of the header's
center of gravity, and the weight Fg of the header 106. Such
instructions are non-transiently stored on a tangible computer
readable medium, such as on a magnetic medium, e.g., a computer
hard drive, an optical medium, e.g., an optical disc, solid-state
memory, e.g., flash memory, or other storage media known in the
art. The instructions may exist in a computer-executable form, such
as machine code, which is the set of instructions and data directly
executed by a computer's central processing unit or by a
controller, a human-understandable form, such as source code, which
may be compiled in order to be executed by a computer's central
processing unit or by a controller, or an intermediate form, such
as object code, which is produced by a compiler. The instructions
also may be stored or accessible in a human-understandable form,
e.g., a script, that may be executed on the fly with the aid of an
interpreter executed by a computer's central processing unit or by
a controller.
[0040] It is envisioned that the computer readable instructions may
be configured to perform the process of determining the position Lg
of the header's center of gravity and the weight Fg of the header
using any of a variety of operations. One example is shown in FIG.
6. Here, the process begins at step 600 by a user activating a
measurement routine. Next, in step 602, the processing unit 312
operates the actuators 304, 306 to place the feeder housing 118 and
header 106 into a predetermined physical relationship relative to
the chassis 102. Such positions may be selected to provide
consistent results without requiring detailed reevaluation of the
geometric relationships of the parts during the measurement
process. For example, the predetermined positions may be to retract
the face plate actuator 306 to a particular angle (e.g., full stop
against the feeder housing 118), and raise the feeder housing 118
until the force on the feeder housing actuator 306 exceeds a
predetermined threshold value known through empirical testing to
indicate that the header 106 is lifted completely off the ground.
Such positions also may be determined and achieved using position
sensors (e.g., potentiometers or the like).
[0041] In step 604, the processing unit 312 measures the values
sensed by the pressure transducers 308, 310. Such values may be
provided, for example, in the form of raw or processed voltage
signals. In step 606, the processing unit 312 converts the sensor
data into respective force values, such as by applying a known
relationship between the fluid pressure within the respective
cylinder and the voltage value output by the sensor, and multiply
the pressure value with the effective area of the piston to
determine a force load. Alternatively, in other exemplary
embodiments, the determination of force values in step 606 may be
done by comparing the sensor signal to a stored lookup table of
pre-established force values corresponding to the sensor output
signal magnitude, or by performing other logical processes. In step
608, the processing unit 312 converts the force values into
equivalent force and distance values, and in step 610 the
processing unit 312 applies the equations above (or comparable
equations) to actively calculate the weight Fg of the header 106,
and the distance Lf in the horizontal direction H from the chassis
102 to the header's center of gravity. Finally, in step 612, the
processing unit 312 presents the calculated values to an operator
via a user interface, such as a computer screen, digital display,
or the like.
[0042] The foregoing process may be modified in various ways. For
example, step 602 may be omitted and replaced by the user manually
operating the actuators to predetermined positions, or the process
may be performed without regard to the positions of the actuators
on the assumption that the values returned will be sufficiently
accurate regardless of how the feeder housing 118 and header 106
are oriented at the time of measurement.
[0043] In another embodiment, the process may be simplified by
omitting the converting and calculating steps (steps 606 through
610), and replacing them with a procedure in which the measured
pressure transducer values are compared to a lookup table stored in
the memory 508. The stored lookup table can include, for example,
predetermined values for the center of gravity position Lg and/or
header weight Fg as a function of the values of the first force F1
and the second force F2.
[0044] It will be appreciated from the present disclosure that the
invention provides a new and useful way to measure the position of
the header's center of gravity, and the weight of the header. The
systems and processes described herein can be used to perform rapid
determinations of these properties upon modifying or replacing a
header, and such information can be used to tune the header control
system to account for the different dynamic properties and
oscillation frequencies of each individual header that is attached
to the combine.
[0045] The foregoing embodiments provide examples of how force
measurements can be used to evaluate the position of the header's
center of gravity and the header's weight. Such force measurements
are implemented in the examples in conjunction with a header 106
that connected to the chassis 102 by a first articulated connection
in the form of a pivot between the feeder housing 118 and the
chassis 102, and a second articulated connection in the form of a
pivot between the header 106 and the feeder housing 118. However,
it will be appreciated that implementations and embodiments may use
alternative physical connections between the various parts,
alternative force measuring gauges, and alternative mechanisms for
controlling the positions of the parts. Other alternatives and
variations will be apparent to persons of ordinary skill in the art
in view of the present disclosure.
[0046] The present disclosure describes a number of inventive
features and/or combinations of features that may be used alone or
in combination with each other or in combination with other
technologies. The embodiments described herein are all exemplary,
and are not intended to limit the scope of the claims. It will also
be appreciated that the inventions described herein can be modified
and adapted in various ways, and all such modifications and
adaptations are intended to be included in the scope of this
disclosure and the appended claims.
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